植物多酚生物利用度及提高方法研究进展

植物多酚与人类健康关系密切,然而其在体内的生物活性受到生物利用度的影响和制约。作者从植物多酚在体内的吸收、代谢、运转过程出发,综述了影响多酚口服生物利用度的因素和现阶段提高多酚口服生物利用度的方法,明确了植物多酚口服生物利用度的研究方向。     

发酵果蔬汁功能特性及生物转化研究进展

多酚具有抗氧化、抗肿瘤、抗动脉硬化、抗炎、抗病毒等生理药理活性,这些健康效应取决于人体对其生物利用度。虽然食品中天然多酚的含量很高,但由于多酚的大分子、稳定性低、被动扩散等原因,其利用率很低。乳酸菌是肠道益生菌,能产乳酸及促进营养物质的吸收,具有抗氧化、抑菌等功能,广泛用于发酵果蔬汁。乳酸菌发酵可将结合酚转化为更易被人体吸收利用的游离酚,提高多酚的生物利用度。该文对乳酸菌发酵果蔬汁中多酚成分经乳酸菌发酵进行代谢转化,提高多酚生物利用度等问题进行综述,以期为开发益于人体健康的发酵果蔬汁提供依据。     

膳食多酚与肠道微生物相互作用研究进展

近年来膳食多酚与肠道微生物的相互作用逐渐成为食品科学、营养学和生物学的研究热点。多酚的抗衰老、抗肿瘤、预防心脑血管疾病的功能发挥主要依赖于肠道微生物对其的代谢;多酚的肠道微生物代谢产物又会通过影响肠道微生物菌相进而影响人体健康。本文在广泛查阅文献的基础上,综述肠道微生物对膳食结合态多酚的释放、代谢和影响因素以及多酚及其代谢产物对肠道微生物菌相和酶的影响,以期为膳食多酚和肠道菌群相互作用的深入研究提供一定参考依据。     

肠道微生物菌群生物转化天然多酚类化合物研究进展

多酚经人体摄入后,由肠道微生物产生的酶分解为更易被人体吸收的酚酸等小分子物质,增加了多酚的生物利用度和活性。这一特性在促进人体健康和食品加工方面有一定的应用潜力。本文综述多酚化合物的分类、多酚在食品中的分布和吸收利用、肠道微生物对多酚的生物转化产物及形成机制等问题,以期为开发益于人体健康的高质量食品和功能性食品提供依据。     

生物利用度模型在纳米载药中的研究与应用

药物的生物利用度是表示药物分子以各种途径或形式进入机体后,经口腔、胃、肠等消化吸收后进入体循环的比例参数。生物利用度是反映药物在生物体内吸收、分布、代谢和排泄情况的重要依据。在医药等领域,纳米药物递送体系是提高活性分子生物利用度非常有效的手段,药物发挥药效时需要从载体中释放才能被充分吸收。在生物活性分子的研发过程中,可通过体外模型和动物体内模型来模拟药物在机体的作用过程,以此推测药物的生物利用度。目前,广泛应用的生物利用度模型主要包括体外模拟释药模型、体外模拟消化模型、细胞模型、体内药代动力学模型等。该研究主要对常见的生物利用度研究模型构建和应用等进行总结,以期为今后纳米药物递送体系的生物利用度模型研究和拓新提供参考。     

食品中微量元素的吸收和代谢

本文介绍了膳食中微量元素生物利用的概念和评估方法（包括化学平衡、摄排速率、血浆特征和同位素示踪等），并扼要阐述了膳食锌、铁、铜、镁、硒等微量元素的代谢情况及相关的影响其吸收代谢的因素。矿物元素是人体必需的五大营养素之一，其吸收和代谢的情况直接影响到人体的生长发育和营养状况。鉴于目前多种微量元素不能被人体很好吸收，故研究膳食和微量元素代谢间的关系有其特殊的营养学意义。在评价不同膳食营养性时有关微量元素摄入吸收情况报道不多；由于影响矿物元素吸收的因素有膳食来源和多种生理原因，故导致有关此方面的研究近几十年来进展缓慢，本文着重综述人体在微量元素吸收代谢方面的最新研究成果，为合理膳食和有效膳食提供借鉴和帮助。     

植物多酚与肠道微生物群的相互作用及其对代谢性疾病影响的研究进展

肠道微生物群参与由胰岛素抵抗、高血糖、血脂异常、中心性肥胖和高血压等组成的代谢综合征的发展,进一步导致代谢性疾病的发生。而植物多酚可以促进肠道微生物群中有益菌的生长,间接减少致病菌的数量。并且肠道微生物群能够将高分子质量的植物多酚代谢为更具生物活性的代谢物以提高其生物利用度。本文综述了植物多酚与肠道微生物群两者之间的相互作用及它们对代谢性疾病的影响,为植物多酚的利用提供参考。     

植物多酚和多糖经肠道微生态途径互作调节糖脂代谢的研究进展

基于“多酚-多糖-肠道菌群”相互作用发挥机体健康效应已成为精准膳食干预策略和生物医学理论基础研究的热点和发展方向。植物多酚和多糖均具有调节机体健康的生物活性,单一组分因自身结构、理化性质等因素导致其生物利用度较低,不能较好的发挥功效。多酚多糖相互作用形成的复合结构能提高其功能特性,从而更有效地发挥机体健康效应和预防疾病。本文主要从多酚多糖调节糖脂代谢的作用、多酚多糖经肠道微生物途径改善糖脂代谢、多酚多糖相互作用调节糖脂代谢机制等方面进行综述。大量前期研究均证实植物多酚和多糖具有糖脂代谢调节功效,然而涉及两种成分相互作用共同发挥功效及其机制研究还非常有限,本综述为后续研究二者相互作用及其功能特性变化等方面提供参考。     

几类不同食物对肠道菌群调节作用的研究进展

肠道菌群是机体的重要组成部分,肠道菌群能在一定程度上影响宿主的营养代谢和健康。肠道菌群的组成与功能受宿主生理状态、遗传、饮食习惯、年龄和环境等多重因素的影响。其中,膳食是影响肠道菌群结构和功能最为重要且较为迅速的因素。作为日常生活中常见的食物资源,杂粮、杂豆和果蔬等食物含有的膳食纤维和多酚等物质已经被证明具有调节肠道菌群的作用。肠道菌群能够发酵膳食纤维,代谢后释放维生素以及短链脂肪酸等代谢产物,并选择性地促进一些肠道有益菌的增殖,进而在一定程度上促进宿主健康。此外,大部分酚类物质也在肠道中被肠道菌群代谢分解后进一步提高酚类物质的生物利用率,从而改善宿主生理状态。本文围绕日常生活中常见的食物资源如杂粮杂豆以及水果蔬菜等对肠道菌群的调节作用进行综述,展望以肠道菌群为靶点的代谢性疾病预防与治疗或膳食干预的前景。     

膳食成分对儿茶素生物利用率的影响及多酚协同增效的研究进展

儿茶素是一种酚类化合物,具有抗过敏、抗氧化、抗炎和抗菌等多种功效,对人体健康有诸多益处。但由于儿茶素热稳定性差、生物利用率较低,膳食摄入的碳水化合物、蛋白质、脂质等物质易与儿茶素在胃肠道中发生相互作用,影响儿茶素的吸收、分布、代谢和排泄过程,进而影响其生物利用率和生理活性。此外,当两种或多种天然多酚类化合物联合应用时可能会产生协同增效作用,可以抑制食品生产加工污染物、降脂减肥、降血糖、抗炎抗菌等。因此,本文主要对膳食成分对儿茶素生物利用率的影响进行综述,阐明了儿茶素和膳食多酚相互作用的机制和两者在协同增效方面的应用前景。     

多酚-膳食纤维相互作用及其影响多酚生物利用率研究进展

多酚广泛存在于植物源食品中,具有潜在的促进人体健康作用。天然多酚绝大多数以结合态存在,并且多酚与膳食纤维结合的比例要显著高于其他基质。多酚和膳食纤维的相互作用在食品加工和机体消化等环节会受到不同因素的影响,从而发生复杂的变化。近年来,多酚-膳食纤维相互作用对多酚生物利用率的影响已经受到了越来越多的关注。本文首先分析了多酚与膳食纤维的不同结合方式,随后总结了影响多酚与膳食纤维相互作用的主要因素,最后探讨了两者相互作用对于多酚生物利用率的影响,可为改善多酚食品的营养健康品质以及提高多酚的生物利用率提供一定的理论参考。     

膳食多酚对淀粉消化吸收的影响

近年来基于食品成分之间相互作用调节食品质地与功能特性的研究成为食品学科的研究热点。多酚与淀粉的相互作用在食品中广泛发生,二者的相互作用对调控加工食品的风味和质地、提高多酚的生物利用度、抑制淀粉的老化以及降低淀粉的消化吸收速度等具有重要作用。综述了多酚与淀粉的复合作用、多酚对淀粉消化酶活性的抑制以及多酚对肠道葡萄糖吸收转运的抑制作用,为利用食物成分与淀粉的相互作用开发预防和控制高血糖症的新型食品提供了参考。     

Bioavailability issues in studying the health effects of plant polyphenolic compounds

Polyphenolic compounds are common in the diet and have been suggested to have a number of beneficial health effects including prevention of cancer, cardiovascular disease, diabetes, and others. For some dietary polyphenols, certain benficial effects are suggested by epidemiological studies, some are supported by studies in animal models, and still others are extrapolated from studies in vitro. Because of the relatively poor bioavailability of many of these compounds, the molecular basis of these beneficial effects is not clear. In the present review, we discuss the potential health benefits of dietary polyphenols from the point of view of bioavailability. Tea catechins, curcumin, and proanthocyanidins are used as examples to illustrate some of the problems that need to be resolved. Further research on both the biological activity and bioavailability of dietary polyphenols is needed to properly assess their usefulness for the prevention and treatment of disease.     

Bioavailability of Quercetin in Humans with a Focus on Interindividual Variation

After consumption of plant‐derived foods or beverages, dietary polyphenols such as quercetin are absorbed in the small intestine and metabolized by the body, or they are subject to catabolism by the gut microbiota followed by absorption of the resulting products by the colon. The resulting compounds are bioavailable, circulate in the blood as conjugates with glucuronide, methyl, or sulfate groups attached, and they are eventually excreted in the urine. In this review, the various conjugates from different intervention studies are summarized and discussed. In addition, the substantial variation between different individuals in the measured quercetin bioavailability parameters is assessed in detail by examining published human intervention studies where sources of quercetin have been consumed in the form of food, beverages, or supplements. It is apparent that most reported studies have examined quercetin and/or metabolites in urine and plasma from a relatively small number of volunteers. Despite this limitation, it is evident that there is less interindividual variation in metabolites which are derived from absorption in the small intestine compared to catabolites derived from the action of microbiota in the colon. There is also some evidence that a high absorber of intact quercetin conjugates could be a low absorber of microbiota‐catalyzed phenolics, and vice versa. From the studies reported so far, the reasons or causes of the interindividual differences are not clear, but, based on the known metabolic pathways, it is predicted that dietary history, genetic polymorphisms, and variations in gut microbiota metabolism would play significant roles. In conclusion, quercetin bioavailability is subject to substantial variation between individuals, and further work is required to establish if this contributes to interindividual differences in biological responses.     

多酚类化合物对糖脂代谢影响的研究进展

多酚类化合物是植物的次生代谢产物,广泛存在于食物中,包括黄酮类化合物、咖啡酸、绿原酸等。很多研究报道表明,摄入富含多酚类化合物的饮料、水果和蔬菜可以减缓肥胖、心血管疾病、糖尿病等慢性疾病甚至癌症的发生和发展。很大一部分原因在于其中的多酚类化合物具有抗氧化、抗病菌、增强免疫力、参与营养成分代谢调节的生理活性。本文结合近年来国内外的研究概况,从相关代谢酶活性和基因的表达、胰岛素分泌、营养物质的消化和吸收等方面来论述多酚类化合物对糖、脂代谢的影响。     

Whole grain rice: Updated understanding of starch digestibility and the regulation of glucose and lipid metabolism

Nowadays, resulting from disordered glucose and lipid metabolism, metabolic diseases (e.g., hyperglycemia, type 2 diabetes, and obesity) are among the most serious health issues facing humans worldwide. Increasing evidence has confirmed that dietary intervention (with healthy foods) is effective at regulating the metabolic syndrome. Whole grain rice (WGR) rich in dietary fiber and many bioactive compounds (e.g., γ-amino butyric acid, γ-oryzanol, and polyphenols) can not only inhibit starch digestion and prevent rapid increase in the blood glucose level, but also reduce oxidative stress and damage to the liver, thereby regulating glucose and lipid metabolism. The rate of starch digestion is directly related to the blood glucose level in the organism after WGR intake. Therefore, the effects of different factors (e.g., additives, cooking, germination, and physical treatments) on WGR starch digestibility are examined in this review. In addition, the mechanisms from human and animal experiments regarding the correlation between the intake of WGR or its products and the lowered blood glucose and lipid levels and the reduced incidence of diabetes and obesity are discussed. Moreover, information on developing WGR products with the health benefits is provided.     

Updated knowledge about polyphenols: functions, bioavailability, metabolism, and health

Polyphenols are important constituents of food products of plant origin. Fruits, vegetables, and beverages are the main sources of phenolic compounds in the human diet. These compounds are directly related to sensory characteristics of foods such as flavor, astringency and color. Polyphenols are extensively metabolized both in tissues and by the colonic microbiota. Normally, the circulating polyphenols are glucuronidated and/or sulphated and no free aglycones are found in plasma. The presence of phenolic compounds in the diet is beneficial to health due to their antioxidant, anti-inflammatory, and vasodilating properties. The health effects of polyphenols depend on the amount consumed and their bioavailability. Moreover, polyphenols are able to kill or inhibit the growth of microorganisms such as bacteria, fungi, or protozoans. Some dietary polyphenols may have significant effects on the colonic flora providing a type of prebiotic effect. The anti-nutrient properties of polyphenols are also discussed in this paper. The antioxidant, anti-inflammatory, vasodilating, and prebiotic properties of polyphenols make them potential functional foods.     

Hydroxycinnamic acids and human health: recent advances

There is an urgent need to improve human diet globally. Compelling evidence gathered over the past several decades suggests that a suboptimal diet is associated with many chronic diseases and may be responsible for more deaths than any other risks worldwide. The main components in our diet that need higher intake are whole grains, fruit and vegetables, and nuts and seeds; all of these are important sources of dietary fiber and polyphenols. The health benefits of dietary fiber and polyphenols are also supported by several decades of valuable research. However, the conclusions drawn from interventional human trials are not straightforward and the action mechanisms in improving human health are not fully understood. Moreover, there is a great inter-individual variation caused by different individual capabilities of processing, absorbing and using these compounds effectively. Data on the bioavailability and bioefficacy of hydroxycinnamic acids (HCAs) are limited when compared to other classes of polyphenols (e.g. anthocyanins). This review aims to summarize the latest research advances related to HCA bioavailability and their biological effects revealed by epidemiological data, pre-clinical and clinical studies. Moreover, we aim to review the effects of HCAs on gut microbiota diversity and function and its respective influence on host health. © 2019 Society of Chemical Industry     

Influence of in vitro gastrointestinal digestion on the bioavailability and antioxidant activity of polyphenols from Ipomoea batatas leaves

Sweet potato leaves (SPL) are natural by‐products rich in bioactive compounds, particularly polyphenols, and can be consumed as a vegetable. This work aims to investigate the influence of in vitro gastrointestinal digestion on the bioavailability and antioxidant activities of polyphenols from SPL. The phenolic compounds of sweet potato leaf extracts (SPLE) were quite stable in gastric phase. However, the amount of phenolic compounds decreased during transition from the acidic gastric environment to the alkaline intestinal environment. The bioavailability of phenolic compounds of SPLE was 13.36%. The ABTS^·+ scavenging capabilities and reducing power of SPLE were not affected during gastric digestion. Antioxidant activity increased after intestinal digestion. This research suggested that phenolic compounds of SPLE were sufficiently available for absorption. This study also provides useful information on the potential commercial value of SPL.     

Stability of polyphenols in chokeberry (Aronia melanocarpa) subjected to in vitro gastric and pancreatic digestion

Berries and red fruits are dietary sources of polyphenols with reported health benefits. As part of the diet, polyphenols are ingested as complex mixtures immersed in a food matrix which is digested in the gut. Epithelial cells lining the gut are regularly exposed to these digested mixtures. To understand the effects of dietary polyphenols on human gut health it is essential to determine their stability and fate in the lumen. In this work, we investigated the effects of an in vitro gastric and pancreatic digestion on the stability and composition of the major polyphenols in chokeberry juice. Digestion was carried out with a mixture of pepsin-HCl for 2 h, followed by a 2 h incubation with pancreatin and bile salts at 37 °C with shaking, in the absence of light and under N₂. After digestion, the chokeberry samples were acidified, filtered and HPLC-DAD/HPLC–MS–MS analysed to determine the content of total soluble recovered phenolics. Gastric digestion had no substantial effect on any of the major phenolic compounds in chokeberry, namely anthocyanins, flavan-3-ols, flavonols and caffeic acid derivatives. However, these compounds were significantly altered during the pancreatic digestion and this effect was more marked for anthocyanins (approximately 43% was lost during the 2 h treatment with pancreatin). Flavonols and flavan-3-ols decreased by 26% and 19%, respectively. Neochlorogenic acid decreased by 28% whereas chlorogenic acid was increased by 24%. In vitro digestion of standard phenolic compounds, representing each of the groups of phenolics in chokeberry, confirmed some of the observed changes. Interactions with the digestive enzymes were not responsible for the observed losses which were mostly due to the chemical conditions during pancreatic digestion. Our results, in accordance with previously published results, show that dietary polyphenols are highly sensitive to the mild alkaline conditions in the small intestine and that a good proportion of these compounds can be transformed into other unknown and/or undetected structural forms with different chemical properties and, consequently, different bioaccessibility, bioavailability and biological activity.